Cover
Title Page
Copyright
Contents
1 Introduction
1.1 Mathematical Models, Solutions, and Direction Fields
Terminology
Solutions and Integral Curves
Initial Value Problems
The Direction Field for u' = –k(u – T)
Solutions and Direction Fields for y' = f (t, y)
Constructing Mathematical Models
1.2 Linear Equations: Method of Integrating Factors
The Method of Integrating Factors for Solving y' + p(t)y = g(t)
1.3 Numerical Approximations: Euler’s Method
1.4 Classification of Differential Equations
CHAPTER SUMMARY
2 First Order Differential Equations
2.1 Separable Equations
2.2 Modeling with First Order Equations
2.3 Differences Between Linear and Nonlinear Equations
2.4 Autonomous Equations and Population Dynamics
2.5 Exact Equations and Integrating Factors
2.6 Accuracy of Numerical Methods
2.7 Improved Euler and Runge–Kutta Methods
CHAPTER SUMMARY
Projects
2.P.1 Harvesting a Renewable Resource
2.P.2 Designing a Drip Dispenser for a Hydrology Experiment
2.P.3 A Mathematical Model of a Groundwater Contaminant Source
2.P.4 Monte Carlo Option Pricing: Pricing Financial Options by Flipping a Coin
3 Systems of Two First Order Equations
3.1 Systems of Two Linear Algebraic Equations
Eigenvalues and Eigenvectors
3.2 Systems of Two First Order Linear Differential Equations
Matrix Notation, Vector Solutions, and Component Plots
Geometry of Solutions: Direction Fields and Phase Portraits
Direction Fields
Phase Portraits
General Solutions of Two First Order Linear Equations
Existence and Uniqueness of Solutions
Linear Autonomous Systems
Transformation of a Second Order Equation to a System of First Order Equations
3.3 Homogeneous Linear Systems with Constant Coefficients
On Reducing x' = Ax + b to x' = Ax
The Eigenvalue Method for Solving x' = Ax
Extension to a General System
Real and Different Eigenvalues
Nodal Sources and Nodal Sinks
Saddle Points
3.4 Complex Eigenvalues
Spiral Points and Centers
3.5 Repeated Eigenvalues
3.6 A Brief Introduction to Nonlinear Systems
3.7 Numerical Methods for Systems of First Order Equations
CHAPTER SUMMARY
Projects
3.P.1 Eigenvalue-Placement Design of a Satellite Attitude Control System
3.P.2 Estimating Rate Constants for an Open Two-Compartment Model
3.P.3 The Ray Theory of Wave Propagation
3.P.4 A Blood-Brain Pharmacokinetic Model
4 Second Order Linear Equations
4.1 Definitions and Examples
Linear Equations
Dynamical System Formulation
The Spring-Mass System
The Linearized Pendulum
The Series RLC Circuit
4.2 Theory of Second Order Linear Homogeneous Equations
Existence and Uniqueness of Solutions
Linear Operators and the Principle of Superposition for Linear Homogeneous Equations
Wronskians and Fundamental Sets of Solutions
Abel’s Equation for the Wronskian
4.3 Linear Homogeneous Equations with Constant Coefficients
The Characteristic Equation of ay" + by' + cy = 0
Initial Value Problems and Phase Portraits
4.4 Mechanical and Electrical Vibrations
Undamped Free Vibrations
Damped Free Vibrations
Phase Portraits for Harmonic Oscillators
4.5 Nonhomogeneous Equations; Method of Undetermined Coefficients
General Solution Strategy
Method of Undetermined Coefficients
Superposition Principle for Nonhomogeneous Equations
Summary: Method of Undetermined Coefficients
4.6 Forced Vibrations, Frequency Response, and Resonance
Forced Vibrations with Damping
The Frequency Response Function
Forced Vibrations without Damping
4.7 Variation of Parameters
Variation of Parameters for Linear Second Order Equations
CHAPTER SUMMARY
Projects
4.P.1 A Vibration Insulation Problem
4.P.2 Linearization of a Nonlinear Mechanical System
4.P.3 A Spring-Mass Event Problem
4.P.4 Uniformly Distributing Points on a Sphere
4.P.5 Euler–Lagrange Equations
5 The Laplace Transform
5.1 Definition of the Laplace Transform
Existence of the Laplace Transform
5.2 Properties of the Laplace Transform
5.3 The Inverse Laplace Transform
Partial Fractions
5.4 Solving Differential Equations with Laplace Transforms
Characteristic Polynomials and Laplace Transforms of Differential Equations
5.5 Discontinuous Functions and Periodic Functions
5.6 Differential Equations with Discontinuous Forcing Functions
5.7 Impulse Functions
5.8 Convolution Integrals and Their Applications
5.9 Linear Systems and Feedback Control
CHAPTER SUMMARY
Projects
5.P.1 An Electric Circuit Problem
5.P.2 Effects of Pole Locations on Step Responses of Second Order Systems
5.P.3 The Watt Governor, Feedback Control, and Stability
6 Systems of First Order Linear Equations
6.1 Definitions and Examples
First Order Linear Systems: General Framework
Applications Modeled by First Order Linear Systems
6.2 Basic Theory of First Order Linear Systems
6.3 Homogeneous Linear Systems with Constant Coefficients
The Matrix A Is Nondefective With Real Eigenvalues
6.4 Nondefective Matrices with Complex Eigenvalues
6.5 Fundamental Matrices and the Exponential of a Matrix
Fundamental Matrices
The Matrix Exponential Function e[sup(At)]
Methods for Constructing e[sup(At)]
6.6 Nonhomogeneous Linear Systems
Variation of Parameters
Undetermined Coefficients and Frequency Response
6.7 Defective Matrices
CHAPTER SUMMARY
Projects
6.P.1 A Compartment Model of Heat Flow in a Rod
6.P.2 Earthquakes and Tall Buildings
6.P.3 Controlling a Spring-Mass System to Equilibrium
7 Nonlinear Differential Equations and Stability
7.1 Autonomous Systems and Stability
7.2 Almost Linear Systems
7.3 Competing Species
7.4 Predator–Prey Equations
7.5 Periodic Solutions and Limit Cycles
7.6 Chaos and Strange Attractors: The Lorenz Equations
CHAPTER SUMMARY
Projects
7.P.1 Modeling of Epidemics
7.P.2 Harvesting in a Competitive Environment
7.P.3 The Rossler System
A: Matrices and Linear Algebra
A.1 Matrices
A.2 Systems of Linear Algebraic Equations, Linear Independence, and Rank
A.3 Determinants and Inverses
A.4 The Eigenvalue Problem
B: Complex Variables
ANSWERS TO SELECTED PROBLEMS
REFERENCES
PHOTO CREDITS
INDEX